I agonize over my varnish work,  I have a larger sailboat with a fair amount of brightwork on it.  Varnishing my SW sport Hybrid, I know every spec of dust, brush stroke, heavy spots, etc.  They all went away when I started using it.  I think, unless it is going in a museum or a show, it is unimportant to have a little dust.  Enjoy what you did, and learn to accept the compliments that you will get, gracefully

you can certainly buff those bits of dust out. With all my preparation moving the kayak to the basement, vacuuming and mopping, I still ended up with some dust particles. But after 6 months of use, the dust specks have been replaced with scuffs from paddle float re-entry practice, the cockpit coaming is getting pretty dinged up and the bottom is really scratched and scruffed. So, I'm resigned to a yearly varnish touch-up and probably a bottom recoat. I agree with dave10990, unless you're building a show boat, don't worry about it. Once you get it into the water, you'll never see those offending dust particles again.  Dave

Automotive rubbing compound works. Try different application materials[cotton, cheese cloth etc.] and do it by hand. Wax can also be applied & buffed out however it could potentially mess with touch-up coats in the future.

Lew